Output speed-controlled transmission

ABSTRACT

An output speed-controlled transmission comprising an input shaft, an output shaft and adjustable drive means through which said input shaft drives said output shaft. Means are provided in association with the output shaft and responsive to the rotational speed thereof; the last mentioned responsive means being operatively related to the drive means to adjust the drive means to maintain a predetermined rotational speed condition of the input shaft.

BACKGROUND OF THE INVENTION

This invention relates to improvements in transmission means and moreparticularly to a unique transmission system having means to govern thedrive speed of its input shaft in accordance with the speed of itsoutput shaft. The transmission is therefore output speed controlled.

The transmission of the present invention has many applications. By wayof example, it may be used as the transmission for self-propelledvehicles such as automobiles, mini-bikes, snowmobiles and pedal operatedvehicles. It may also be used in association with the drive means invarious types of machinery. In addition, it may serve as a speedgovernor. For purposes of illustration, the transmission of the presentinvention will be described in respect to various of its applicationsand particularly with reference to pedal operated vehicles. However, itwill be obvious that the application is not so limited and such is notintended.

In efforts to produce more efficient transmissions, prior art workershave devised a number of means to control drive train ratio. Thesecontrollers, however, are responsive to the input shaft speed.Furthermore all prior control systems related to control of drive trainratios known to applicants require an increase in the speed of the inputshaft of the transmission to produce an increase in the speed of itsoutput shaft.

For example, in a standard hydraulic automatic transmission inautomotive applications, the gear train ratio is controlled primarily bythe speed of the automobile engine. That is, by increasing engine speed,hydraulic pressure changes effect change in the transmission ratio andthe transmission output speed is correspondingly increased. Inconventional pulley belt transmissions, centrifugal weights or the likein the transmission input shall effect a decrease in pulley ratio withan increase in the input shaft speed.

The present invention is directed to an output speed-controlledtransmission wherein the control of the respective speeds of the inputand output shafts is determined by means in association with thetransmission output shaft and responsive to its speed. The inventiontransmission may be so designed as to effect an increase in the speed ofrotation of the input shaft in correspondence with and as a result ofthe speed of rotation of the output shaft. In addition, however, itoffers two distinct capabilities, after initial start-up, not inherentin conventional systems. The output speed controlled transmission may beso designed as to have the input shaft turned at a speed which isdecreased in respect to the output shaft speed and vice versa. Thetransmission may also be arranged to maintain a constant speed at theinput shaft with an increasing output shaft speed.

A prime feature of the invention is its inherent capabilities indiminishing air pollution in use of an internal combustion engine.

In the automotive field, for example, much attention has recently beengiven to the problems of emissions control. One of the primarydifficulties lies in the fact that for each automotive engine speedthere are many variables (such as air-fuel ratio, spark advance, camtiming and the like) to be considered for the minimizing of emissions.Since the optimum conditions of these variables will change fordifferent engine speeds, it is substantially impossible to design anengine which optimizes the variables to produce minimum emissions forthe full range of operating engine speeds. Through the use of thetransmission of the present invention, however, the engine speed couldremain at a predetermined constant regardless of the vehicle speed(after an initial change of engine speed during startup) and thevariables could be adjusted to give minimum emissions at thatpredetermined speed. Furthermore, this predetermined engine speed couldbe so chosen as to cause the engine to operate at its maximum poweroutput speed, regardless of the automobile speed.

In a number of vehicles, such as minibikes, snowmobiles and the like,which currently employ pulley belt systems, the engine speed increaseswith vehicle speed with the result that the vehicle speed is limited bythe engine speed and not by the power required to drive the vehicle athigh speed. Through the use of the transmission of the presentinvention, the maximum speed potential of such vehicles could berealized since at high vehicle speeds the engine could be made tooperate at a safe speed at which it produces maximum horsepower.

Pedal powered devices such as bicycles and the like are prime examplesof vehicles, the speed of which is limited by the input speed. Toovercome this problem, prior art workers have devised systems employingup to 15 different gear ratios. These systems are complex, however, andrequire the slipping of a chain from one gear to another to effect aratio change. The application of the present transmission to a bicyclewould enable the cyclist to pedal at a constant speed (after an initialstartup phase) regardless of the bicycle speed and no manual gearchanges would be required. This will be particularly described.

The transmission of the present invention may also be used with manytypes of electric motor-powered devices. When an electric motor is usedto drive a piece of equipment characterized by high inertia, theelectric motor tends to accelerate to its operational speed before theequipment during startup. This, in turn, can result in excessive beltslippage. Through the use of the present transmission, the motor couldoperate at its maximum power speed during startup without belt slippage.

The output speed-controlled transmission of the present invention, inpreferred embodiment, is of the pulley belt type, but contrary to theusual prior art structures, it does not require skewing of the belt andconsequent accelerated belt wear. The transmission may be provided withmanually or automatically controlled override means, as will bedescribed hereinafter. Furthermore, it may employ various types of shaftspeed sensors, again as will be described hereinafter.

SUMMARY OF THE INVENTION

In preferred embodiment the transmission of the present inventioncontemplates the use of an input shaft and an output shaft rotativelysupported in parallel spaced relationship. Each of these shafts has apulley assembly mounted thereon. Each of the pulley assemblies is atwo-piece structure made up of a first half non-rotatably and fixedlymounted on its respective shaft and a second half non-rotably mounted onthe same shaft, but capable of axial movement along the shaft toward andaway from its respective fixed pulley half. The pulley halves making upeach pulley assembly are conical in configuration so as to define abouttheir periphery a V-shaped groove to receive a V belt. The V beltconnects the input and output shaft pulley assemblies.

A shaft speed sensing means is provided in association with thetransmission output shaft and is so designed as to move the shiftableoutput shaft pulley half toward and away from its respective fixed halfin response to the output shaft speed. Any appropriate transducersensitive to the output shaft speed may be employed such as centrifugalmeans, a hydraulic sensor, an electric sensor or an electro-magneticsensor.

The transmission also has means to cause the shiftable pulley half onthe input shaft to move simultaneously and oppositely toward and awayfrom its respective fixed pulley half when the output movable pulleyhalf is shifted.

The input shaft of the transmission may be pedal driven or connected tothe shaft of an internal combustion engine, an electric motor or thelike. The output shaft of the transmission, in automotive applications,will be connected to the rear wheels of the automobile through aforward-neutral-reverse box (as is known in the art) and a conventionaldifferential. The transmission output shaft, on the other hand, may beconnected directly to the input shaft of an appropriate machine or otherelement to be driven. In bicycle applications, or the like, the outputshaft will be connected to the bicycle rear wheel through conventionalchain-sprocket means.

A manually or automatically controlled override may be provided inassociation with the transmission to counteract the action of the outputshaft speed sensing means when required. It is also within the scope ofthe invention to mechanically connect the shiftable halves of the inputand output shaft pulley assemblies to assure their proper andsimultaneous movement.

Finally, it is within the scope of the present invention to arrange theoutput shaft speed sensing means in such a way that it will shift themovable half of the input shaft pulley assembly (rather than the outputshaft pulley assembly) in response to the output shaft speed.

A primary object of the invention is to provide a unique output speedcontrolled transmission having multiple applications which is easy tofabricate, more efficient and satisfactory in use and adaptable to awide variety of applications without danger of malfunction.

Another object of the invention is to provide an improved transmissionunit applicable for use with internal combustion engines and the like toreduce the potential for air pollution for use of such apparatus.

An additional object of the invention is to provide output controlledtransmission units possessing the advantageous structural features, theinherent meritorious characteristics and the means and mode of useherein described.

With the above and other incidental objects in view as will more fullyappear in the specification, the invention intended to be protected byLetters Patent consists of the features of construction, the parts andcombinations thereof, and the mode of operation as hereinafter describedor illustrated in the accompanying drawings, or their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view, partly in cross section, of the transmission ofthe present invention as applied to a pedal-driven vehicle.

FIG. 2 is a fragmentary plan view of another embodiment of thetransmission for a pedal-driven vehicle.

FIG. 3 is a cross sectional plan view of yet another embodiment of theoutput speed controlled transmission of the present invention for usewith a pedal-driven vehicle.

FIG. 4 is a fragmentary plan view, partly in cross section, illustratinga modification of the embodiment of FIG. 3.

FIG. 5 is an elevational view of a bicycle provided with a transmissionof the type shown in FIGS. 3 or 4.

FIG. 6 is a fragmentary elevational view, partly in cross section, ofanother embodiment of the output speed controlled transmission of thepresent invention.

FIG. 7 is a fragmentary elevational view illustrating a modified form ofspeed sensing means for the output shaft of the transmission.

FIG. 8 is a fragmentary view, partly in cross section, illustrating analternate cam groove configuration for the embodiment of FIG. 6.

EMBODIMENT OF THE PREFERRED EMBODIMENTS

A basic embodiment of the output speed controlled transmission of thepresent invention, as applied to a pedal-driven vehicle such as abicycle, is illustrated in FIG. 1. In FIG. 1 an input shaft 1 is shownmounted in a bearing means 2 affixed to the bicycle frame (not shown).The input shaft 1 has angularly related ends 3 and 4 provided withpedals 5 and 6, respectively. A housing 7 surrounds the transmission andthe input shaft 1 extends through a perforation 8 in the housing.

The input shaft 1 supports a pulley assembly generally indicated at 9.The pulley assembly comprises a first pulley half 9a fixedly andnon-rotatively mounted on the input shaft 1 in any appropriate manner,as by pins 10. A second pulley half 9b is non-rotatively mounted on theinput shaft 1 but is axially shiftable therealong toward and away frompulley half 9a. The mounting of pulley half 9b may be accomplished inany appropriate way. For example, the input shaft 1 may be provided witha pair of diametrically opposed slots 11 and 12 adapted to receive keys13 and 14 affixed to pulley half 9b. The keys will prevent rotation ofthe pulley half with respect to the shaft 1, but will permit a shiftingof the pulley half axially of the shaft, within the limits of the slots11 and 12.

The transmission of FIG. 1 also includes an output shaft 15. The outputshaft is rotatively mounted in suitable bearings 16 and 17 in thehousing 7. One end of the output shaft 15 extends through an opening 18in the housing and carries a chain sprocket 19. The chain sprocket 19 isconventional and may be connected to a drive sprocket (not shown) on therear wheel of the bicycle (not shown) by a drive chain (not shown), allas is conventional in the art.

The output shaft 15 of the transmission carries a pulley assemblygenerally indicated at 20. The pulley assembly 20 comprises a firstpulley half 20a fixedly and non-rotatively mounted to the shaft in thesame manner described with respect to pulley half 9a above. The pulleyassembly includes a second pulley half 20b non-rotatively affixed to theoutput shaft but axially shiftable thereon. The pulley half 20b may bemounted on shaft 15 in the same manner described with respect to pulleyhalf 9b. The pulley assemblies 9 and 20 are connected by a V-belt 21.

The embodiment of FIG. 1 is provided with a centrifugal type speedsensing means for the output shaft 15. The shiftable pulley half 20b hasa cylindrical extension 22 terminating in an annular flange 23 bearingcam rollers 24 and 25. A mounting means 26 is provided havingcentrifugal weights 27 and 28 pivoted thereon. The centrifugal weights27 and 28 have cam surfaces cooperating with the cam rollers 24 and 25,respectively. The mounting means 26 is rotatable with pulley half 20band output shaft 15, but is not axially shiftable with respect to outputshaft 15. This may be accomplished by affixing the mounting means 26 tothe shaft 15 through longitudinal slots in the cylindrical extension 22.Control spring means 29 is located between mounting means 26 and thepulley half 20b.

It will be evident that as the rotational speed of output shaft 15 andmounting means 26 increases, the centrifugal weights 27 and 28 willpivot outwardly. The cam surfaces on these weights will cooperate withcam rollers 24 and 25 to shift the assembly comprising the flange 23,cylindrical extension 22 and pulley half 20b toward the left as viewedin FIG. 1 (i.e., away from pulley half 20a). The amount of shiftimparted by the weights 27 and 28 will depend upon the configuration ofthe cam surfaces thereon. The amount by which the weights 27 and 28pivot outwardly will, in turn, depend upon the rotational speed of shaft15 and the action of control springs 29. Upon a reduction in rotationalspeed of output shaft 15, cam weights 27 and 28 will swing inwardlytoward output shaft 15 with the influence of control springs 29 thuspermitting pulley half 20b to move toward pulley half 20a.

As indicated above, pulley assemblies 9 and 20 are joined by a V-belt21. In order for the desired transmission ratio change to take place, itis required that shiftable pulley half 9b on input shaft 1 movesimultaneously and oppositely when shiftable pulley half 20b on outputshaft 15 is moved, so that the slack in V-belt 21 is appropriately takenup. By "oppositely" is meant that as pulley half 20b moves away frompulley half 20a, pulley half 9b will shift toward pulley half 9a, andvice versa.

To accomplish appropriate corresponding movements of pulley halves 9band 20b, these pulley halves may be mechanically connected by a yokemeans generally indicated at 30. The yoke means comprises a cylindricalelement 31 mounted on a shaft 32 extending between opposite side wallsof housing 7 and in parallel spaced relationship with input shaft 1 andoutput shaft 15. The cylindrical element 31 is axially shiftable withrespect to shaft 32.

At one end the cylindrical element 31 has an arm 33. The arm 33 has aperforation 34 through which output shaft 15 extends. An appropriatethrust bearing 35 is mounted in the perforation 34 in abutment withflange 23 of pulley half 20b.

The cylindrical element 31 carries at its other end a second arm 36having a perforation 37 through which the input shaft 1 extends. Athrust bearing 38 and sleeve 39 are operatively attached to shiftablepulley half 9b. A spring 40 surrounds the sleeve 39. One end of thespring is in abutment with the sleeve 39 and thrust bearing 38. Theother end of the spring is in abutment with yoke arm 36.

The spring 40 serves two purposes. First of all, it assures that the arm33 of the yoke structure is always in contact with the structure ofpulley half 20b. Furthermore, it assures that the pulley assemblies 9and 20 will exert sufficient force on V-belt 21 to prevent slippagethereof.

The yoke assembly 30, just described, assures proper movement of pulleyhalves 9b and 20b. It also maintains correct alignment of V-belt 21 whenone pulley is opened and the other is closed, thereby minimizing skewingof the belt and consequent accelerated wear thereof.

It will be understood by one skilled in the art that it is within thescope of the invention to eliminate the yoke assembly 30. Under thesecircumstances, the right hand end of spring 40 (as viewed in FIG. 1)will be provided with an appropriate abutment means. Under thesecircumstances, the spring 40 will be relied upon to cause the pulleyassemblies to maintain proper tension on V-belt 21 and to cause orpermit pulley half 9b to shift toward or away from pulley half 9a uponthe occurrence of an axial shift of pulley half 20b whichcorrespondingly moves belt 21 in or out, in a radial sense referenced toshaft 15.

The operation of the output speed-controlled transmission of FIG. 1 maybe described as follows. By appropriate selection of control springs 29and by appropriate configuration of the cam surfaces on weights 27 and28, the transmission may be designed to allow the cyclist to pedal at aconstant speed (after initial startup) regardless of the bicycle speed.

After the initial startup phase, if an increase in bicycle speed isdesired, increased torque on input shaft 1 by the cyclist is transmittedto the rear or driving wheel of the bicycle through theoutput-controlled transmission. The increased torque at the rear wheelof the bicycle will accelerate it. As the bicycle begins to changespeed, a simultaneous change in speed of the transmission output shaft15 will occur. This increase in speed of output shaft 15 will result inan outward swinging of centrifugal weights 27 and 28. The amount ofoutward swing of weights 27 and 28 with the increase in speed of outputshaft 15 will be determined primarily by control springs 29.

Outward movement of centrifugal weights 27 and 28 will result in anaxial shift of pulley half 20b away from pulley half 20a by virtue ofthe cooperation of the cam surfaces on weights 27 and 28 and the camrollers 24 and 25 on flange 23. The amount of axial shift of pulley half20b with respect to the swing of centrifugal weights 27 and 28 will beprescribed by the configuration of the cam surfaces on weights 27 and28.

The axial shift of pulley half 20b away from pulley half 20a will causea simultaneous and opposite shift of pulley half 9b toward pulley half9a by virtue of the yoke assembly 30. Thus, simultaneously, the openingof pulley assembly 20 is translated through the yoke assembly 30 to aclosing of pulley assembly 9. The relative opening of pulley assembly 20and closing of pulley assembly 9 causes the belt 21 to shift outwardlyon pulley assembly 9 and inwardly on pulley assembly 20. Thus a newtransmission ratio is established.

When the bicycle speed is reduced to that speed determined by thestartup phase, the various elements of the transmission will function ina manner opposite to that just described. Thus, the centrifugal weights27 and 28 will swing inwardly toward the output shaft 15 and the pulleyassembly 20 will be closed while the pulley assembly 9 will be opened.In this manner, the original transmission ratio after the startup phasewill be reestablished.

Since, as indicated above, the transmission may be designed to allow thecyclist to pedal at a constant speed (after initial startup) regardlessof the bicycle speed, the bicycle speed is not limited by the inputshaft speed and no manual gear changes or complex gear systems arerequired.

FIG. 2 illustrates a modification of the transmission of the presentinvention wherein the speed sensing device, responsive to the outputshaft speed, causes a shift of a pulley half of the pulley assembly onthe input shaft. Again, for purposes of an exemplary showing, theembodiment of FIG. 2 is illustrated as applicable to a pedal vehicle,although it is not intended to be so limited in application.

In the Figure an input shaft 41 is shown having angularly related ends41a and 41b provided with pedal means, one of which is shown at 42. Theinput shaft 41 and its pedal means are equivalent to input shaft 1 andpedal means 5 and 6 of FIG. 1. The input shaft 41 is rotatively mountedin bearings 43 and 44 in a housing 45.

A cylindrical output shaft is shown at 46. The output shaft isconcentric with and is rotatively mounted on the input shaft 41 by meansof appropriate bearings 47 and 48. The output shaft 46 has a pulleyassembly thereon generally indicated at 49. The pulley assemblycomprises a first half 49a fixedly and non-rotatively mounted on theoutput shaft in the manner described above. The pulley assembly 49 has asecond pulley half 49b non-rotatively mounted on the output shaft butcapable of axial shifting therealong toward and away from pulley half49a. The mounting of pulley half 49b on output shaft 46 may beaccomplished as described above.

A third shaft 50 is rotatively mounted in bearings 51 and 52 in thehousing 45. The shaft 50 is in parallel spaced relationship to inputshaft 41 and output shaft 46.

Input shaft 41 has, non-rotatively mounted thereon, a cog wheel 53.Shaft 50 is provided with a cog wheel 54 non-rotatively mounted thereon.Cog wheels 53 and 54 are joined by cog belt 55. As a consequence ofthis, the shaft 50 may also be considered to be the input shaft, beingan extension of input shaft 41. This is true since the rotationalmovement of shaft 41 is imparted to shaft 50 by cog belt 55.

Shaft 50 mounts a pulley assembly generally indicated at 56. This pulleyassembly comprises a first pulley half 56a and a second pulley half 56b.Pulley half 56a is fixedly and non-rotatively mounted on shaft 50.Pulley half 56b is non-rotatively mounted to the shaft, but is capableof axial shifting therealong toward and away from pulley half 56a. Themounting of pulley halves 56a and 56b may be accomplished in the mannerset forth above. From the structure thus far described, pulley assembly56 may be considered to be the input pulley assembly while pulleyassembly 49 may be considered to be the output pulley assembly. Thepulley assemblies are joined by a V-belt 57.

The output shaft 46 has a sprocket 58 thereon. This sprocket may beconnected by conventional chain means (not shown) to the rear wheelsprocket of the bicycle (not shown), as is known in the art.

Output shaft 46 has non-rotatively affixed thereto a cog wheel 59. This,in turn, is connected by a cog belt 60 to a cog wheel 61 on shaft 50.Cog wheel 61 has a cylindrical sleeve portion 61a and is rotativelymounted on shaft 50 by suitable bearing means 62 and 63. Cog wheel 61carries a pair of cam rollers 64 and 65.

A cylindrical sleeve 66 surrounds the cylindrical extension 61a of cogwheel 61 and is non-rotatively mounted thereon; but sleeve 66 is axiallyshiftable with respect to cog wheel portion 61a. This may beaccomplished by providing portion 61a with at least one pair ofdiametrically opposed longitudinal slots 67 and 68 and providing thesleeve 66 with a pair of cooperating keys 69 and 70. The sleeve 66 haspivotally affixed thereto as at 71 and 72 a pair of centrifugal weights73 and 74, respectively. These weights have cam surfaces coacting withcam rollers 64 and 65. An end of sleeve 66 contacts shiftable pulleyhalf 56b through a thrust bearing 75.

From the assembly just described, it will be noted that the speed ofoutput shaft 46 will be transmitted by cog wheel 59 and cog belt 60 tocog wheel 61. At the same time, this rotational speed will also betransmitted to sleeve 66 and the centrifugal weights 73 and 74 mountedthereon. As the rotational speed of output shaft 46 increases, thecentrifugal weights 73 and 74 will shift outwardly and their coactionwith cam rollers 64 and 65 will cause the sleeve 66 together with pulleyhalf 56b to move toward pulley half 56a.

A spring 76 is mounted on shaft 50 and its ends abut pulley halves 56aand 56b. It will be understood that the spring 76 serves substantiallythe same purpose as control springs 29 of FIG. 1 and will govern theamount by which the centrifugal weights 73 and 74 swing outwardly inresponse to the rotational speed of output shaft 46. The amount by whichpulley half 56b is shifted toward pulley half 56a will be determinedlargely by the cam surfaces on the centrifugal weights 73 and 74, and byspring 76.

To accomplish the required simultaneous and opposite movement of pulleyhalf 49b toward pulley half 49a, a spring 77 is mounted on output shaft46. The spring 77 abuts the sprocket 58 at one end and the pulley half49b at the other.

The operation of the embodiment of FIG. 2 is substantially identical tothat of FIG. 1. Thus, as the rotational speed of output shaft 46increases, so will the rotational speed of the sensing means orcentrifugal weights 73 and 74. Their outward movement will cause a shiftof pulley half 56b toward pulley half 56a. This, in turn, will result ina movement of pulley half 49b away from pulley half 49a thus changingthe pulley ratio. Again, proper selection of spring 76 and appropriateconfiguration of the cam surfaces on centrifugal weights 73 and 74 maybe provided to maintain the speed of input shaft 41 constantirrespective of the speed of output shaft 46 (after the initial startupphase).

FIGS. 3 and 5 illustrate a more sophisticated and preferred version ofthe output-controlled transmission of the present invention as appliedto a bicycle. Turning first to FIG. 5, a conventional bicycle isillustrated having a main frame 78 supporting a front wheel 79, a rearwheel 80, a seat 81, handle bars 82 and a conventional pedal and drivesprocket assembly 83. In this embodiment, the transmission generallyindicated at 84 comprises a housing 85 rotatively mounted on the rearaxle 86 of the bicycle. The housing 85 forms the hub for rear wheel 80and the rear wheel is supported thereon by conventional spokes, some ofwhich are illustrated at 87. The conventional pedal drive sprocketassembly 83 is connected by a cog chain 88 to a drive sprocket 89 forthe transmission.

For a complete understanding of the transmission, reference is made toFIG. 3. In FIG. 3 the rear axle 86 is shown appropriately andnon-rotatively mounted on the bicycle frame 78. The transmission housing85 comprises an annular rim-like structure 90 and two circular sideportions 91 and 92. The side portions 91 and 92 are affixed to therim-like portion 90 by screws or other appropriate means 93. It will beunderstood (see FIG. 5) that the rear wheel is affixed to and supportedby the housing 85 by means of the spokes 87 (not shown in FIG. 3). Thehousing 85 is rotatable on the rear axle 86 by appropriate bearing means94 and 95.

Within the housing, a pair of frame members 96 and 97 are non-rotativelymounted on the rear axle 86. The frame members 96 and 97 support aninput shaft 98 in suitable bearing means 99 and 100. The input shaft 98is equivalent to input shaft or shaft extension 50 in FIG. 2. The sameframe members also support an output shaft 101 in appropriate bearingmeans 102 and 103. The output shaft 101 is equivalent to output shaft 46of FIG. 2.

The input shaft carries an input shaft pulley assembly, generallyindicated at 104. The assembly 104 comprises a first pulley half 104afixedly attached to input shaft 98 by any appropriate means includingset screw 105. A second pulley half 104b is non-rotatively mounted oninput shaft 98, but is shiftable axially thereof toward and away frompulley half 104a. Again, this can be accomplished in any appropriatemanner. For example, as described above, the input shaft 98 may have alongitudinal slot 106 in which a key 107 on pulley half 104b is located.

The output shaft 101 carries an output shaft pulley assembly, generallyindicated at 108. This assembly comprises a first pulley half 108afixedly and non-rotatively mounted on output shaft 101 by anyappropriate means including set screw 109. A second pulley half 108b isnon-rotatively mounted on output shaft 101. Pulley half 108b however, isshiftable axially of the output shaft 101 toward and away from pulleyhalf 108a. As in the case of the input shaft, the output shaft 101 maybe provided with a longitudinal slot 110 to receive a key 111 on pulleyhalf 108b. The pulley assemblies 104 and 108 are joined by a V-belt 112.

The transmission drive sprocket 89 is rotatively mounted on rear axle 86and is operatively connected to a second drive sprocket 114 by ratchetmeans 89a permitting free wheeling as is known in the art. The drivesprockets 89 and 114 are mounted between bearing means 95 and bearingmeans 115. It will be noted that sprockets 89 and 114 are rotatabletogether, but independently of the housing 85.

As illustrated in FIG. 5, sprocket 89 is connected to the pedal anddrive sprocket assembly 83 by drive chain 88 (not shown in FIG. 3). Thesprocket 114, in turn, is connected by a cog belt 116 to a sprocket 117fixedly mounted on input shaft 98. Sprocket 114, chain 116 and sprocket117 are equivalent to sprocket 53, cog belt 55 and sprocket 54 of FIG.2.

It will be evident from the above description that rotation imparted tosprocket 89 by pedal and drive sprocket assembly 83 and chain 88 willalso be imparted to input shaft 98 through the agency of sprocket 114,chain 116 and sprocket 117. Through the agency of V-belt 112, rotationof input shaft 98 and its pulley assembly 104 will be transmitted topulley assembly 108 and output shaft 101. Output shaft 101 has, at oneend, a sprocket 118, connected by chain 119 to another sprocket 120. Thesprocket 120 is affixed to the portion 91a of housing side 91. Thus, therotation of output shaft 101 will, through sprocket 118, chain 119 andsprocket 120, be imparted to the housing 85. Since the housing 85, inturn, is the hub of rear wheel 80, this rotation will be imparted to therear wheel. Sprocket 118 may be considered to be equivalent to sprocket58 of FIG. 2.

As in the case of the embodiment of FIG. 2, the sensing means for therotational speed of the output shaft is mounted on the input shaft andcauses a shifting of input shaft pulley half 104b toward and away fromfixed pulley half 104a. To this end, pulley half 104b has a rearwardcylindrical extension 104c. Rotatively mounted on this extension is asleeve 121. The sleeve 121 has an annular interior flange 122 and a pairof arms 123 and 124 bearing racks 125 and 126, respectively.

A second sleeve 127 surrounds the sleeve 121 and is rotatable therewithby virtue of the key 128 affixed to sleeve 127 and riding in alongitudinal slot 129 in the periphery of sleeve 121. The sleeve 127 hasan in-turned flange portion 130 at one end. The flange portion 130terminates in an L-shaped portion 131. The L-shaped portion 131 rides ona bearing means 132. The remainder of sleeve 127 is supported by sleeve121, which in turn rides on bearing means 133 mounted on the extension104c of pulley half 104b.

Sleeve 127 carries a pair of arms 134 and 135 to which are pivotallyaffixed gear segments 136 and 137, respectively. The gear segments 136and 137 are adapted to cooperate with racks 125 and 126, respectively.Each of gear segments 136 and 137 carry centrifugal weights 138 and 139,respectively.

The sleeve 127 also carries a sprocket 140. The sprocket 140 isconnected by a chain 141 to a sprocket 142 mounted on output shaft 101.

With respect to the structure just described, it will be evident thatrotation of output shaft 101 will be communicated by sprocket 142, chain141 and sprocket 140 to sleeves 127 and 121, which are keyed together.As the rotation of the assembly of sleeves 127 and 121 increases,centrifugal weights 138 and 139 will swing outwardly and away from inputshaft 98. Through the agency of gear segments 136 and 137 and thecooperating racks 125 and 126, the sleeve 121 will be shifted to theleft, as viewed in FIG. 3. This shifting of sleeve 121 will cause asimilar shifting of pulley half 104b toward pulley half 104a. This istrue because the interior annular flange 122 of sleeve 121 bears againstbearing 133 which in turn bears against pulley half 104b.

A plurality of springs 143 may be located within sleeve 121. One end ofeach of the springs 143 abuts the flange 122 of sleeve 121. The otherend of each of the springs 143 abuts the portion 130 of sleeve 127. Thepurpose of springs 143 will be described hereinafter.

A control spring 144 is mounted on input shaft 98. The ends of controlspring 144 abut pulley halves 104a and 104b. Control spring 144 isequivalent to control spring 76 of FIG. 2 and serves the same purposes.

Finally, a spring 145 is mounted about output shaft 101. One end ofspring 145 abuts shiftable pulley half 108b. The other end of the springabuts a cup-shaped flange 146 mounted on the output shaft. Spring 145 isequivalent to spring 77 of FIG. 2 and serves the same purposes, i.e., itassures proper shifting of pulley half 108b upon shifting of pulley half104b and that proper tension is maintained on V-belt 112.

The operation of the embodiment of FIG. 3 is essentially the same asthat described with respect to FIG. 2. After the initial startup phase,the rotational speed of output shaft 101 will be sensed by thecentrifugal weights 138 and 139 since the rotation of output shaft 101is imparted to the weights through the agency of sprocket 142, chain 141and sprocket 140. As the rotational speed of output shaft 101 increases,the weights will swing outwardly. Gears 136 and 137, cooperating withracks 125 and 126, respectively, will cause a shift of sleeve 121 andthus pulley half 104b toward pulley half 104a. This same cooperation ofthe racks and gears will maintain sleeve 127 in its proper position. Theclosing of pulley assembly 104 will result in an opening of pulleyassembly 108 and the desired ratio change. Again, racks 125 and 126 andgears 136 and 137, together with control spring 144, may be so chosenand configured that the cyclist (after initial startup) may pedal at aconstant speed regardless of the bicycle speed. Again, the bicycle speedis not limited by the input shaft speed and no manual gear changes orcomplex gear systems are required. The embodiment of FIG. 3 has thefurther advantage that it is fully enclosed and located within rearwheel 80 (see FIG. 5).

It will be noted that when the transmission is at rest the pulleyassemblies 104 and 108 and V-belt 112 will assume the positions shown inFIG. 3, under the influence of springs 144 and 145. The function ofsprings 143 is to assist the centrifugal weights in their outwardmovement to maintain the proper force balance necessary to achieve thedesired predetermined rotational speed condition of the input shaft 98.

FIG. 4 illustrates a modification of the embodiment of FIG. 3. Likeparts have been given like index numerals. The embodiment of FIG. 4differs from that of FIG. 3 in that the pulley assembly on the outputshaft and the spring in association therewith to maintain proper tensionon the V-belt float with respect to the output shaft. This arrangementassures, among other things, that the V-belt does not become skewedduring shifting of the pulley assemblies, thus eliminating undue wear onthe V-belt 112. This embodiment also makes better and more efficient useof the space within the housing 85.

In the embodiment of FIG. 4, the output shaft is shown at 101a. Theoutput shaft is mounted in a manner identical to that described withrespect to FIG. 3. A bearing sleeve 147 is slidably mounted on theoutput shaft. The sleeve is non-rotatable with respect to the outputshaft, by virtue of the fact that the output shaft is provided with alongitudinal slot 148 in which a key 149 affixed to sleeve 147 islocated. While the sleeve 147 will rotate with output shaft 101a, itwill also shift axially thereof within the limits of the slot 148.

A second sleeve is shown at 150. The sleeve 150 is affixed to the sleeve147 and rotates therewith. The output shaft pulley assembly is indicatedat 108c and comprises a first pulley half 108d fixedly secured to sleeve150 by any suitable means such as set screw 109a. A second pulley halfis shown at 108e. This pulley half is rotatable with sleeves 150 and 147and input shaft 101a and is axially shiftable therealong toward and awayfrom pulley half 108d. This is accomplished by providing sleeve 150 witha longitudinal slot 150a in which is located a key 151 affixed to pulleyhalf 108e. It will be noted from the structure thus far described thatthe fixed and shiftable pulley halves have been reversed with respect tothose shown in FIG. 3.

The sleeve 150 carries at one end a cuplike flange 152 held on thesleeve 150 by a clamping ring 153. In this embodiment, a pair of springs154 and 155 are located about the sleeve 150. One end of each of thesesprings abuts the flange 152, while the other end of each of thesesprings abuts pulley half 108e. The springs 154 and 155 serve the samepurpose as spring 145 in FIG. 3.

Except for the modifications just described, the embodiment of FIG. 4 isotherwise identical to the embodiment of FIG. 3 and its operation is thesame.

Another basic form of the output-controlled transmission of the presentinvention is illustrated in FIG. 6. In that Figure, an input shaft isshown at 156 and an output shaft is shown at 157. The input shaft 156 isrotatively mounted in appropriate bearing means 158 and 159 in a framestructure 160 and 161, respectively. It will be understood by oneskilled in the art that the frame structure 160-161 may constitute ahousing for the transmission. In similar fashion, the output shaft 157is supported by frame members 160 and 161 in suitable bearing means 162and 163. It will be noted that the input shaft 156 and output shaft 157are in parallel spaced relationship.

An input shaft pulley assembly is generally indicated at 164. The pulleyassembly is made up of two halves 164a and 164b. It will be noted thatthe halves 164a and 164b have conical surfaces 164c and 164d,respectively, sloping inwardly and toward each other. As in the previousembodiments, these surfaces define a V-shaped notch. The pulley half164a is non-rotatively and fixedly mounted on the input shaft 156. Thismounting may again be accomplished in any one of a number of suitableways including pinning as at 165 and 166.

The pulley half 164b is non-rotatively affixed to the input shaft 156but is shiftable axially of the input shaft toward and away from pulleyhalf 164a. This, again, may be accomplished in any number of well knownways. As in FIG. 1, the input shaft 156 is shown provided with at leastone diametrical pair of longitudinal slots 167 and 168 and the pulleyhalf 164b is illustrated as provided with keys 169 and 170 adapted to beslidably received in the slots 167 and 168, respectively.

As output shaft pulley assembly is generally indicated at 171. As in thecase of the input shaft pulley assembly 164, the output shaft pulleyassembly 171 is made up of two halves 171a and 171b presenting facingconical surfaces 171c and 171d, respectively. These surfaces also form aV-shaped notch.

The output shaft pulley half 171a is non-rotatively and fixedly mountedon the output shaft, again by any appropriate means such as pins 172 and173. The output pulley half 171b is non-rotatively mounted on the outputshaft 157, but is axially shiftable thereon toward and away from pulleyhalf 171a. Again, this mounting may be accomplished in any appropriatemanner as by means of shaft slots 174 and 175 and pulley keys 176 and177.

Pulley half 171b has a cylindrical extension 178 thereon of lesserdiameter than the pulley half body, and defining an annular shoulder179. A cylindrical member 180 is non-rotatively affixed to the pulleyhalf extension 178, again by any suitable means such as pins or setscrews 181 and 182. The member 180 has formed thereon a pair of ears 183and 184 having cam grooves 185 and 186. It will be noted that the member180, by virtue of its attachment to the pulley half extension 178, isnon-rotatable relative to the output shaft 157, but is axially shiftabletherealong together with the pulley half 171b.

A mounting means 187 is non-rotatively and fixedly mounted on the outputshaft 157 by any appropriate means such as pins or set screws 188 and189. The mounting means 187 has pivotally affixed thereto as at 190 and191 a pair of centrifugal weights 192 and 193, respectively. The weights192 and 193, in turn, bear rollers 194 and 195 adapted to ride in thecam grooves 185 and 186, respectively, of the member 180.

It will be understood from the structure thus described that as thespeed of the output shaft 157 is increased, the centrifugal weights 192and 193 will pivot outwardly about the pivot points 190 and 191,respectively. As a consequence of this, rollers 194 and 195 will moveoutwardly in cam grooves 185 and 186, respectively. This, in turn, willcause the pulley half 171b to move away from the fixed pulley half 171athereby widening the V-shaped groove between the pulley halves 171a and171b.

Means may be provided to regulate the movement of centrifugal weights192 and 193. To this end, the mounting means 187 has an annular ring 196shiftably mounted thereon. There is also an annular flange 197constituting an integral part of the mounting means 187. A plurality ofcontrol springs 198 are located between the flange 197 and the ring 196.The centrifugal weights 192 and 193 bear extensions carrying rollers 199and 200, respectively. The rollers 199 and 200 engage the ring 196.Thus, the outward movement of centrifugal weights 192 and 193 is againstthe action of control springs 198.

It will be evident that the maximum amount of shifting of the movablepulley half 171b is determined by the pulley keys 176 and 177 and theirrespective shaft slots 174 and 175. The range of movement of pulley half171b within this maximum capability will be governed by control springs198 and the configuration of cam grooves 185 and 186, in cooperationwith the centrifugal weights 192 and 193. By appropriate configurationof the cam grooves 185 and 186 and by careful selection of controlsprings 198, the shifting of pulley half 171b in response to the speedof the output shaft 157 can be fully controlled.

Pulley assemblies 164 and 171 are connected by a V-belt 201. As in theprevious embodiments, in order for the desired transmission ratio changeto take place, it is necessary that shiftable pulley half 164b on theinput shaft 156 move simultaneously and oppositely at the time when theshiftable pulley half 171b on output shaft 157 is moved so that theslack in V-belt 201 is appropriately taken up.

To accomplish appropriate corresponding movements of pulleys halves 164band 171b, these pulley halves may be mechanically connected by a yokemeans generally indicated at 202 and substantially identical to yokemeans 30 of FIG. 1. The yoke means comprises a cylindrical element 203mounted on a shaft 204 extending between frame members 160 and 161 andin parallel spaced relationship with input shaft 156 and output shaft157. The cylindrical element 203 is axially shiftable with respect toshaft 204 by means of appropriate bearing elements 205 and 206.

At one end the cylindrical element 203 has an arm 207. The arm 207 has aperforation 208 through which the output shaft 157 and the extension 178of the pulley half 171b passes. An appropriate thrust bearing 209 islocated between the arm 207 and the shoulder 179 of the pulley half171b.

The cylindrical element 203 carries at its other end a second arm 210which has a perforation 211 therethrough. The input shaft 156 passeswith clearance through the perforation 211. About the perforation 211there is an annular depression 212 formed in the arm 210. Thisdepression is adapted to receive one end of spring 213. The other end ofspring 213 abuts an annular flange 214 on a sleeve 215 which surroundsan extension 216 on pulley half 164b. The extension 216 is of lesserdiameter than the pulley body forming an annular shoulder 217. A thrustbearing 218 is located between the sleeve flange 214 and the pulleyshoulder 217.

As in the case of spring 40 of FIG. 1, the spring 213 serves twopurposes. First of all, it assures that the arm 207 of yoke assembly 202is always in contact with thrust bearing 209 and therefore pulley half171b. Furthermore, it assures that the pulley assemblies 164 and 171will exert sufficient force on V-belt 201 to prevent slippage thereof.

Again, the yoke assembly 202 assures proper movement of pulley halves164b and 171b. It also maintains correct alignment of V-belt 201 whenone pulley is opened and the other is closed, thereby minimizing skewingof the belt and consequent accelerated wear thereof.

As in the embodiment of FIG. 1, it is within the scope of the inventionto eliminate the yoke assembly 202. Under these circumstances, the righthand end of spring 213 (as viewed in FIG. 6) will be provided withappropriate abutment means. The spring 213 will be relied upon to causethe pulley assemblies to maintain proper tension on the V-belt 201 andto cause pulley half 164b to shift toward or away from pulley half 164aupon the occurrence of an axial shift of pulley half 171b.

Operation of the output-control transmission of FIG. 6 may be describedas follows. For purposes of explanation, let it be assumed that thetransmission is in its application as an automotive transmission. Underthese circumstances, the input shaft 156 will be connected to the outputshaft of the automobile engine (not shown) through a clutch (not shown).The output shaft 157 of the transmission will be connected to the rearwheel assembly of the automobile (not shown) through a standarddifferential (not shown) and a conventional forward-neutral-reverse gearassembly (not shown). Let it further be assumed that the control springs198 are so chosen and the cam grooves 185 and 186 are so configured thatafter an initial startup phase the automobile engine is intended tooperate at a constant speed.

After the initial startup phase, if an increase in vehicle speed isdesired, the operator will depress the accelerator pedal. This causes anincrease in throttle opening of the engine intake system which in turncauses the engine torque output to increase. The increased engine torqueis transmitted to the differential and drive wheels of the vehiclethrough the output-controlled transmission and theforward-neutral-reverse gear assembly. The increased torque at the rearwheels of the vehicle will accelerate the vehicle. As the vehicle beginsto change speed, a simultaneous change in speed of the transmissionoutput shaft 157 will occur. This increase in speed of output shaft 157will result in an outward swinging of centrifugal weights 192 and 193.The amount of radial displacement of weights 192 and 193 with theincrease in the speed of output shaft 157 will be determined primarilyby control springs 198.

Outward movement of centrifugal weights 192 and 193 will result in anaxial shift of pulley half 171b away from pulley half 171a by virtue ofweight rollers 194 and 195 in cam slots 185 and 186 of member 180affixed to the extension 178 of pulley half 171b. The amount of axialshift of pulley half 171b with respect to the radial movement ofcentrifugal weights 192 and 193 will be prescribed by the configurationof cam grooves 185 and 186.

The axial shift of pulley half 171b away from pulley half 171a willcause a simultaneous and opposite shift of pulley half 164b towardpulley half 164a by virtue of the yoke assembly 202. Thus,simultaneously, the opening of pulley assembly 171 is translated throughthe yoke assembly 202 to a closing of pulley assembly 164. The relativeopening of pulley assembly 171 and closing of pulley assembly 164 causesthe belt 201 to shift outwardly on pulley assembly 164 and inwardly onpulley assembly 171. Thus a new transmission ratio is established.

When the vehicle speed is reduced to that speed determined by thestartup phase, the various elements of the transmission will function ina manner opposite to that just described. Thus, the centrifugal weights192 and 193 will swing inwardly toward the output shaft 157 and thepulley assembly 171 will be closed while the pulley assembly 164 will beopened. Thus, the original transmission ratio after the startup phasewill be reestablished. When the control springs 198 are appropriatelychosen and the cam slots 185 and 186 are appropriately configured, theengine speed will remain constant throughout the above described speedupand slowdown procedure. If, thereafter, the vehicle is brought to ahalt, it will be understood that during the stop phase reduction ofspeed of the output shaft 157 will be accompanied by a reduction ofspeed of the input shaft 156.

Under some circumstances, it may be desirable to provide a manually orautomatically controlled over-ride which will apply an external force tocounteract the controlling centrifugal force of the assembly of FIG. 6.For example, in an automotive application if the normal operational modewould be for constant engine speed above the startup phase to minimizeemissions, higher power demands (such as those required in passing)could be achieved through the over-ride to effect a change in numericaldrive ratio to correspond to a higher power output engine speed.

An exemplary over-ride is illustrated in FIG. 6. The over-ride comprisesa hydraulic cylinder 219 having a piston 220 and piston rod 221. It willbe understood that the cylinder 219 may be manually or automaticallyactuable.

The piston rod 221 is operatively connected to the arm 210 of yokeassembly 202. Thus, an axial shifting of the piston rod 221 will shiftthe yoke assembly 202. This, in turn, through cam grooves 185 and 186will move the centrifugal weights 192 and 193 as well as the pulley half171b and the pulley half 164b. Thus, a new numerical drive ratio will beestablished. It will be understood by one skilled in the art that otherwell known means may be employed to shift the yoke assembly 202 andthereby counteract the control of centrifugal weights 192 and 193.

In each of the embodiments thus far described a centrifugal weightassembly has been described as serving as a sensing-transfer transducerto sense a change in the output shaft speed and to transfer this to aratio change. It will be understood by one skilled in the art that anytransducer sensitive to the output shaft speed could be employed toproduce the same effect. To illustrate this, a hydraulicsensing-transfer transducer is illustrated in FIG. 7.

In FIG. 7, a transmission output shaft is fragmentarily illustrated at222. The shaft 222 may be equivalent to output shaft 157 of FIG. 6, forexample. The movable half of an output shaft pulley assembly is shown at223 and may be equivalent to shiftable pulley half 171b of FIG. 6. Asdescribed above, pulley half 223 is non-rotatably mounted on shaft 222,but is axially shiftable therealong. This may be accomplished byproviding a longitudinal slot 224 in the shaft 222. Pulley half 223 hasa key 225 receivable and slidable within the shaft slot 224. Pulley half223 will be engaged by a V-belt 226 which may be the same as belt 201 ofFIG. 6.

Pulley half 223 has a rearward cylindrical extension 227 to which ismounted a pair of ears 228 and 229 bearing cam grooves 230 and 231. Thepair of ears 228 and 229 and their cam grooves are equivalent to themember 180 and its cam grooves (see FIG. 6).

A support 232 is non-rotatively and fixedly secured to the output shaft222. A pair of links 233 and 234 are pivotally affixed to the support232 as at 235 and 236, respectively. The free ends of links 233 and 234bear cam rollers 237 and 238 adapted to ride in cam grooves 230 and 231,respectively. It will be evident from the structure thus far describedthat as the free ends of links 233 and 234 move away from the outputshaft 222, the rollers thereon will coact with the cam grooves 230 and231 to move the pulley half 223 to the left, as viewed in FIG. 7.Similarly, movement of the free ends of links 233 and 234 toward theoutput shaft 222 will cause a shift of pulley half 223 toward the right,as viewed in FIG. 7. To control this movement, a control spring 239 ismounted on output shaft 222. One end of the spring 239 abuts the end ofthe cylindrical extension 227 of pulley half 223. The other end ofspring 239 abuts the support 232. Thus, outward movement of the freeends of links 233 and 234 and a shifting of pulley half 223 toward theleft will be controlled by spring 239. In this manner, spring 239 servesthe same purpose as described with respect to control springs 198 ofFIG. 6. By appropriate selection of spring 239 and by appropriateconfiguration of cam grooves 230 and 231, the ratio change accomplishedby the transmission can be determined as desired.

A friction wheel 240 is non-rotatively affixed to output shaft 222. Thiswheel coacts with a friction wheel 241 on the rotor 242 of a hydraulicpump 243. It will be understood that wheels 240 and 241 may be gears.The output 244 of the hydraulic pump is connected to a cylinder 245, thepiston rod 246 of which is operatively connected to links 233 and 234 bydisc member 247. The end of piston rod 246 is captively held in anannular groove 248 in the disc member. The disc member 247 is slotted toreceive links 233 and 234. The links themselves are slotted as at 249and 250. Pins 251 and 252, affixed to the disc member 247, ride in thelink slots 249 and 250.

It will be understood that the pump 243 will produce a hydraulicpressure proportional to the speed of output shaft 222. An increase inshaft speed will cause retraction of piston rod 246. As a consequence ofthis, the links 233 and 234 will be moved outwardly by the disc member247 and pulley half 223 will be moved toward the left in FIG. 7.

FIG. 7 may also be considered as representing an electric sensor. Insuch an instance, the pump 243 may be considered to be an electricgenerator and the cylinder 245 may be considered to be a solenoid. Thegenerator 243 will produce a voltage input to solenoid 245 proportionalto the speed of output shaft 222. The rod 246, now a solenoid core, willmove pulley half 223 in the same manner described above and withincreased force as the generated voltage increases, brought about by anincrease in speed of the output shaft 222.

As indicated above, the transmission of the present invention can be sodesigned and the cam grooves can be so configured as to accomplish adecreasing input shaft speed with an increasing output shaft speed. FIG.8 illustrates an alternate configuration of cam groove 185 in ear 183 ofcylindrical member 180 of FIG. 6. Such a configuration of cam grooves185 and 186 in the embodiment of FIG. 6 will result in a decreasinginput shaft speed with an increasing output shaft speed.

An example of the useful application of such a transmission is as aspeed governor for a vehicle such as an automobile. In such an instance,the output-controlled transmission would be so designed so that thecentrifugal forces would begin to activate the control at apredetermined vehicle speed, for example, at 80 miles per hour. Underthese circumstances, the transmission of the present invention would beemployed as a governor only and would be in addition to a regularautomobile transmission. It could be incorporated in the casing of theregular transmission so that the regular transmission output shaft isconnected to the input shaft of the instant transmission and the outputshaft of the instant transmission becomes the output shaft of thetransmission-governor combination.

In such an application, for all types of vehicle operation up to 80miles an hour the transmission of the present invention, acting as agovernor, would execute no control and would have no effect on theoperating characteristics of the vehicle. However, when the vehiclespeed reaches 80 miles per hour, a further increase in vehicle speed(i.e., a further increase in the rotational speed of the governor outputshaft) would actuate the centrifugal mechanism or other sensing means tocause the rotational speed of the input shaft of the governor and thusthe speed of the automobile engine to decrease.

As the vehicle speed increases, more power must be supplied by theengine to overcome increased wind resistance and the like. Automobileengines develop power which ideally increases linearly with enginespeed. Thus, as the vehicle speed increases and the engine speeddecreases under the influence of the governor, the power required todrive the vehicle increases but the power available from the enginedecreases. The rate at which the speed of the input shaft of thegovernor decreases with increased speed of the output shaft isdetermined by the shape of the cam grooves. This shape could be designedsuch that as the vehicle reaches 90 miles an hour, the engine speedwould have attained the point where the maximum power developed wouldequal the power required to drive the vehicle and no further increase invehicle speed would be possible.

This arrangement differs markedly from conventional governor means whichlimit engine speed rather than vehicle speed and are controlled byengine speed rather than vehicle speed. Thus, conventional governors canlimit vehicle speed but have the disadvantage of also limiting theacceleration capabilities of the vehicle when driving below the limitingvehicle speed. By employing the output-controlled transmission of thepresent invention as a governor, the vehicle could realize its fullacceleration potential at normal speeds and yet be limited in ultimatespeed.

Modifications may be made in the invention without departing from thespirit of it.

Having thus described my invention, I claim:
 1. An outputspeed-controlled automatic transmission comprising an input shaft and anoutput shaft, adjustable drive means through which said input shaftdrives said output shaft, means associated with said output shaft andresponsive to the rotational speed thereof, said responsive means beingoperatively related to said drive means to adjust said drive means tochange the transmission ratio between said input and output shafts inresponse to changes in rotational speed of said output shaft.
 2. Thestructure claimed in claim 1 wherein said responsive means includesmeans for maintaining the rotational speed of said input shaft constantwhen said output shaft is rotating at and about a predetermined speed.3. The structure claimed in claim 1 wherein said responsive meansincludes means to reduce the rotational speed of said input shaft whensaid rotational speed of said output shaft exceeds a predeterminedrotational speed.
 4. The structure claimed in claim 1 wherein saidresponsive means includes means to increase the rotational speed of saidinput shaft when said output shaft rotational speed increases.
 5. Anoutput speed-controlled automatic transmission comprising an input shaftand an output shaft, adjustable drive means through which said inputshaft drives said output shaft, comprising belt carrying means on eachof said input and output shafts, means in association with both of saidbelt carrying means to adjust their effective diameters, and a beltmounted on and interconnecting said input shaft and output shaft beltcarrying means, means associated with said output shaft and responsiveto the rotational speed thereof, said responsive means being operativelyrelated to said adjustable drive means to adjust the effective diametersof said input shaft and output shaft belt carrying means in response tochanges in rotational speed of said output shaft.
 6. An outputspeed-controlled automatic transmission comprising an input shaft and anoutput shaft, adjustable drive means through which said input shaftdrives said output shaft, comprising an input pulley assembly on saidinput shaft, an output pulley assembly on said output shaft, a beltconnecting said input and output pulley assemblies and means to increasethe effective diameter of one of said input and output pulley assembliesand to simultaneously decrease the effective diameter of the other ofsaid input and output pulley assemblies in response to changes inrotational speed of said output shaft.
 7. The structure claimed in claim1 wherein said output speed-controlled transmission is mounted on abicycle of the type having a pedal drive and at least one driven wheel,said input shaft being operatively connected to said pedal drive andsaid output shaft being operatively connected to said driven wheel. 8.The structure claimed in claim 6 wherein each of said input and outputpulley assemblies comprises a pair of pulley halves mounted on therespective one of said input and output shafts for rotation therewith,said pulley halves of each of said pairs having facing surfaces forminga substantially V-shaped notch for said belt, one pulley half of eachpair being shiftable longitudinally of its respective shaft toward andaway from the other pulley half of that pair, whereby to vary theeffective diameters of said pulley assemblies, said means responsive tosaid rotational speed of said output shaft being operatively connectedto said shiftable pulley half of one of said input and output pulleyassemblies to shift said pulley half in response to said rotationalspeed of said output shaft and means to assure a simultaneous andopposite shift of said shiftable pulley half of the other of said inputand output pulley assemblies.
 9. The structure claimed in claim 6wherein said means responsive to the rotational speed of said outputshaft includes centrifugal weights mounted in said transmission forrotation by said output shaft, said weights being swingable from aretracted position toward an extended position as the rotational speedof said output shaft increases and vice versa, said centrifugal weightsbeing operatively connected to said adjustable drive means toselectively adjust said drive means as said weights swing between saidretracted and extended positions.
 10. The structure claimed in claim 8wherein said means to assure a simultaneous and opposite shift of saidshiftable pulley half of said other of said input and output pulleyassemblies comprises yoke means mechanically connecting said shiftablepulley halves of said input and output pulley assemblies.
 11. Thestructure claimed in claim 8 wherein said means responsive to therotational speed of said output shaft includes centrifugal weightsmounted in said transmission for rotation by said output shaft, saidweights being swingable from a retracted position toward an extendedposition as the rotational speed of said output shaft increases and viceversa, said weights being operatively connected to said shiftable pulleyhalf of one of said input and output pulley assemblies to shift saidpulley half as said weights swing between said retracted and extendedpositions.
 12. The structure claimed in claim 8 wherein said means toassure a simultaneous and opposite shift of said shiftable pulley halfof said other of said input and output pulley assemblies comprisesspring means operatively connected to said last mentioned shiftablepulley half.
 13. The structure claimed in claim 8 including means toover-ride said means responsive to said rotational speed of said outputshaft.
 14. The structure claimed in claim 11 wherein said weights aresupported by means mounted on said output shaft for rotation therewith,said weights being operatively connected to said shiftable pulley halfof said output shaft pulley assembly.
 15. The structure claimed in claim11 including support means for said weights to which said weights arepivotally attached, said support means being rotatably mounted on saidinput shaft, said weights being operatively connected to said shiftablepulley half of said input shaft pulley assembly and means whereby saidweights and support means therefor are rotated independently of saidinput shaft rotation by said output shaft.
 16. The structure claimed inclaim 7, wherein said output speed controlled transmission is comprisedin a unitary means forming a hub of said driven wheel, said unitarymeans including a housing having a rim portion in supporting relation tosaid driven wheel, a relatively stationary frame in said housingmounting said input and output shafts with said adjustable drive meansin an interconnecting relation to said shafts, means providing a drivingconnection through said housing from the pedal drive to rotate saidinput shaft, and means establishing a rotary driving connection fromsaid output shaft to said housing.
 17. An output speed-controlledautomatic transmission comprising an input shaft and an output shaft,said transmission being mounted on a bicycle of the type having a pedaldrive and at least one driven wheel, said transmission being comprisedin a unitary means forming a hub of said driven wheel, said unitarymeans including a housing having a rim portion in supporting relation tosaid driven wheel, a relatively stationary frame in said housingmounting said input and output shafts, adjustable drive means in aninterconnecting relation to said shafts, said adjustable drive meansincluding a variable ratio belt type transmission, means providing adriving connection through said housing from the pedal drive to rotatesaid input shaft, means establishing a rotary driving connection fromsaid output shaft to said housing, and means responsive to therotational speed of said output shaft to change the speed ratio betweensaid input and output shafts in response to changes in rotational speedof said output shaft, said responsive means being a shaft speed sensingmeans associated with said output shaft, both said adjustable drivemeans and said responsive means being wholly contained in said housing.18. An output speed controlled automatic transmission comprising aninput shaft and an output shaft, adjustable drive means through whichsaid input shaft drives said output shaft, comprising a variable ratiobelt type transmission including variable diameter pulleys on saidshafts and an interconnecting belt, a shaft speed sensing meansassociated with said output shaft and means operating from said shaftspeed sensing means to vary the diameter of said pulleys in a relativelyinverse sense.